public override async Task Apply(CADDocument doc, params string[] args)
{
Editor ed = doc.Editor;
ed.PickedSelection.Clear();
var p1 = await ed.GetPoint("Start point: ");
if (p1.Result != ResultMode.OK)
{
return;
}
var p2 = await ed.GetPoint("End point: ", p1.Value);
if (p2.Result != ResultMode.OK)
{
return;
}
QuadraticBezier cons = new QuadraticBezier(p1.Value, Point2D.Average(p1.Value, p2.Value), p2.Value);
doc.Jigged.Add(cons);
var p3 = await ed.GetPoint("Control point: ", (p) => cons.P1 = p);
doc.Jigged.Remove(cons);
if (p3.Result != ResultMode.OK)
{
return;
}
Drawable newItem = new QuadraticBezier(p1.Value, p3.Value, p2.Value);
doc.Model.Add(newItem);
}
private void AddParabola(Point2D site)
{
if (m_root == null)
{
m_root = new VParabolaNode(site);
}
else if (m_root.EnumerateLeaves().All((leaf) => leaf.Site.Y == site.Y))
{
// Degenerate case - all parabola sites on the same y-value.
// If this happens, then our edge starts between us and our nearest point, and we need
// to force affected edges (left and right) to recalculate their edge starts.
var cutParabola = m_root.GetParabolaByX(site.X, site.Y);
var newParabola = new VParabolaNode(site);
var middle = Point2D.Average(cutParabola.Site, newParabola.Site);
// store old parabola parent so we can append junction node there
var cutParent = cutParabola.Parent;
// note: edge ctor appends child parabolas to itself.
VEdgeNode edge;
if (cutParabola.Site.X < newParabola.Site.X)
{
edge = new VEdgeNode(middle, Vector2D.UnitXPlus, cutParabola, newParabola);
}
else
{
edge = new VEdgeNode(middle, Vector2D.UnitXPlus, newParabola, cutParabola);
}
// append edge node to old cutparabola parent
if (cutParent != null)
{
if (cutParent.Left == null)
{
cutParent.Left = edge;
}
else
{
cutParent.Right = edge;
}
}
}
else
{
var cutParabola = m_root.GetParabolaByX(site.X, site.Y);
// store old parabola parent so we can append junction node there
var cutParent = cutParabola.Parent;
// :: determine the parabolas left and right of the cut parabola. This is important
// :: for the "Swallowing" of parabolas by circle events.
var cutParabolaLeft = (VParabolaNode)cutParabola.GetLeftLeaf();
var cutParabolaRight = (VParabolaNode)cutParabola.GetRightLeaf();
// :: determine the left, middle, and right parabolas formed by this cut.
var left = cutParabola;
var middle = new VParabolaNode(site);
var right = cutParabola.Clone();
// :: determine where the new "middle" parabola meets the "cut" parabola
var intersection = cutParabola.CalculatePointAtX(site.X, site.Y);
// create the left and right edges...
var vCutMiddle = middle.Site - cutParabola.Site;
var rightDirection = vCutMiddle.Perp(); // performs 90deg counterclockwise rotation in euclidean space
var leftDirection = rightDirection.Flip();
var leftEdge = new VEdgeNode(intersection, leftDirection, left, middle);
var rightEdge = new VEdgeNode(intersection, leftDirection, leftEdge, right);
if (cutParent.Left == null)
{
cutParent.Left = rightEdge;
}
else
{
cutParent.Right = rightEdge;
}
// :: Manage Circle Events
// Unregister the cut parabola node's event, which is now invalidated.
if (cutParabola.CircleEvent != null)
{
m_queue.Remove(cutParabola.CircleEvent);
cutParabola.CircleEvent = null;
}
// Register the left, right, and middle circle events
if (cutParabolaLeft != null)
{
RegisterCircleEvent(cutParabolaLeft, left, middle);
}
if (cutParabolaRight != null)
{
RegisterCircleEvent(middle, right, cutParabolaRight);
}
if (cutParabolaLeft != null && cutParabolaRight != null)
{
RegisterCircleEvent(left, middle, right); // wtf? Shouldn't be necessary, right?
}
}
}
